This invention relates to a method and accompanying apparatus for manufacturing a shell-shaped package, and a resulting package formed thereby.
A prior art method for manufacturing a shell-shaped package is disclosed in European patent specification 0 369 549.
The drawback of the prior art method is that the material bands, before the longitudinal edges thereof are machined, must be separated by means of a separating element, such as for instance a plate or board, in connection with the fact that the edges of the packages that define the wide opening are to be machined in different manners so as to obtain a package that is simple to open.
Another disadvantage of the prior art method is that two pairs of cutting dies are necessary to machine the material bands, viz. one pair on one side of the separating element and one pair on the other side of the separating element. Such cutting dies are subject to wear, so that they must be replaced regularly, which is particularly costly.
Prior art apparatus for manufacturing a shell-shaped package is disclosed in European patent specification 0 369 549. The prior art apparatus comprises a separating element and four cutting and/or perforating dies, viz. one pair on each surface side of the plate-shaped separating element. The prior art apparatus is very costly owing to the presence of the separating plate, the two pairs of cutting dies and the two displacement mechanisms associated with the cutting dies.
A prior art shell-shaped package, too, is disclosed in European patent specification 0 369 549. The drawback of the prior art package resides in the fact that it can only be manufactured with much effort because one wide opening side of the package projects relative to the other wide opening edge. In the prior art package, one of the package portions comprises a suspension portion which is connected to the relevant package portion via a perforated line.